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one of the questions that we get a lot from fellow YouTube viewers is a question about grounding and you've done a good job in one of you well all your books you keep hashing it out the grounding chapter do you want to give a little bit of a sort of a recap of your mind of about grounds and what are the gotchas around grounds for  pleasure voters related to DC Systems aboard boats sure I mean the first thing is the we've got several different grounding systems on a boat which is why it gets confusing we have the AC grounding system in our AC systems we may have DC grounding for example if an inverter is properly installed it should have a case ground and also many battery chargers and then we have bonding which is another form of grounding for corrosion control and we have bonding for lightning protection so we have multiple grounding systems on the boat sometimes related to the same piece of equipment so so that in itself is confusing the core one that I think we should focus on first Jeff is the AC grounding because that's fundamental to safety and on all of our boats the cases of most of our AC equipment should be in some way grounded so that if we get an internal fault now fault current is carried safely back to the source but for that to work if the source is Shore power the AC system also has to be tied to the boat's grounding system and to the water in some way otherwise there is no path to shore power and then once we do that we create the potential for galvanic corrosion through the shore power connection so then we need to have either an isolation Transformer or a galvanic isolator so there's a there's a lot of quite complicated technical issues related to the AC grounding system and typically we treat it separately from the other grounding systems it has its own circuit and its own third wire within the AC conductors within the same common sheath and it just has that common connection point to them to the boat's grounding system so we can in a sense take that out of the equation because that is a self-contained system that has that point of connection to the boat's grounding system and then we've got the others we've got the DC grounding we've got the bonding we've got the lining protection there's no reason to have three separate conductors for all of these circuits we only need one conductor because they're all saving serving the same purpose which is to hold all of the bits of equipment at the same potential the the rule is that the conductor has to be the largest one that is required for the different grounding perspectives so if you're grounding for  Corrosion Prevention bonding it's supposed to be an 8 gauge  copper conductor minimum if it's lightning it's six gauge so if you're trying to combine those two you'll go up to six gauge if it's DC grounding it's got to be  no smaller than one size under the DC negative to the equipment so if we're talking an inverter with tool conductors you know positive and negative to it that grounding conductor has to be at least a one or conductor and then of course you don't need additional lightning and bonding conductors so so we can combine all of these conductors into a single conductor we just have to make sure it's large enough to deal with the worst case fault condition it might have to encounter and for example I've seen windlasses which have been bonded for lightning protection where the six gauge conductor where there's been an internal fault within the windlass a short so all of a sudden that six gauge conductor is carrying fault current which might be hundreds of amps and then the conductor melts down because it's not sized to handle the worst case fault current and it's generally in a bundle with other conductors so then in melting down it melts all the other conductors and then you have to rewire the bow and all of a sudden that single error in terms of sizing that one conductor has gotten you into a project that's going to cost potentially thousands of dollars in sorting out the issues if it hasn't already set the boat on fire but typically it doesn't it just melts down and does a lot of damage to other conductors and then you have to do an extent of rewiring yeah so true the you have a lot of salt water fresh water marinas so then we have a separate issue and I just talked earlier about the AC grounding system connected to the to the post grounding system which has a connection to the water if you have a fault when you're plugged into shore power or their fault current can end up in the water and in fresh water environment like you've got in in many of your marinas on Lake Union and so on that can kill somebody we call it electric shock drowning so then we need an additional piece of kit on those boats which is an electric leakage circuit interrupter which before 2013 wasn't installed on any American Billboards but for those of your listeners that are operating in that freshwater environment in the Seattle area or anywhere else with older boats they need to retrofit the shore power circuit with one of those electric leakage circuit interrupters which are not expensive and it's not that big a job but it's a really critical piece of safety equipment yeah good point so in the Pacific Northwest the challenges you're right there's a lot of marinas that are in coves where there's fresh water inflow even though the salt water is it's the ocean there's so much fresh water coming in that the top layer is fresh water as you mentioned not conductive and so if you're swimming at the surface like a child might be or yeah that's the that's a real danger and  one why many Marine operators  forbid people swimming in Marinas because not many of us unfortunately have those elcis blue Seas makes a good kit that you talk about the Big Challenge installing it is finding the space in between the shore power Inlet and the AC panel  finding a place where you can mount that surface mount box but it's doable it's definitely doable and it's not it's rarely impossible it's just you're bringing a good point Nigel it's just it's just a challenge to do it and yeah that's a real threat people do literally die from a drowning that is maybe not understood as  electrification electrocution I think is the word I'm having a hard time pronouncing it but yeah it's a real threat real threat in local water fundamentally nobody should swim in freshwater around any boat that's plugged into Shore power correct oh now in salt water you can get a belt you know somebody cleaning a propeller for example if there's a fault on the boat and you might get a pretty nasty belt off the prop but  in  fresh water I mean salt water rather you might get a belt off it but in fresh water it's potentially lethal so nobody should ever swim around the boat  in fresh water that's plugged into Shore power yeah so if you're curious again go on our website and find out more answers and solutions with this sort of setup and thanks for asking and thanks for all of you for listening and tuning in